Current Edition: 2019

Purchase your copy here

The Thirteenth edition of Canada’s national concrete standard CSA A23.1 “Concrete materials and methods of concrete construction” was published June 28, 2019 along with CSA A23.2 “Test methods and standard practices for concrete”.

Significant technical changes:

Two new Standard Practices for A23.2-24C “Standard practice for sampling, testing, and inspection of concrete for qualification and acceptance purposes” and A23.2-25C “Standard Practice for sampling, testing, and inspection of concrete for acceptance purposes”.

Mass concrete thermal control planning with new Annex T.

Concrete mixes for interior floors shall have a slump of 120 ± 30 mm at the point of discharge.

Granular bases shall be level to +/- 10mm prior at the time of concrete placement (see Position Statement).

Slab on grade wire mesh must be chaired.

Steel fibres may now be certified in compliance with European Standard CE EN14889-1 or must be accompanied by a Certificate of Compliance and Test Reports in accordance with ASTM A820.

The Concrete Purchaser shall receive the concrete materials on site and ensure that it is placed in the correct location.

Annex P Sulphide minerals updated.

Annex S Concrete with carbon dioxide.

New Annex U on ultra-high performance concrete (UHPC).

New test method A23.2-26C “Bulk electrical resistivity of concrete” measuring penetration of fluids and aggressive ions.

and much more.

Other important considerations:

Under-slab vapour retarders shall be installed in areas with non-breathing finishes and shall comply with ASTM E1745 and ASTM E1643.

The average slab on grade thickness shall be no more than 10mm less than the specified thickness and no local variations in excess of 20mm less than the specified thickness.

Owners shall specify concrete mixes, curing and reinforcing as necessary to control drying shrinkage curling to meet their specific needs.

Sawcut contraction joints shall be spaced at approximately 25 times the slab thickness in metres and shall not exceed 4.5m on centre unless specialty mixes are involved.

Semi-rigid joint fillers should not be filled earlier than 120 days after slab casting (see Position Statement).

The Concrete Purchaser must make suitable arrangements for the plastic protection of the concrete mix being used (see Position Statement).

Surface tolerances shall be measured within 72 hours of slab casting when used for acceptance or rejection purposes (See Position Statement).

The F Number System is the only approved means of measuring floor tolerances in Canada (with an exception for small slab on grade areas up to 1500 sf see Table 21)

Levelness tolerances do not apply to suspended slabs.

The minimum local value (60% of overall specified value) must be exceeded in all areas.

A machine trowel finish shall not be used on air-entrained concrete to avoid the potential for surface delaminations.

Test method 16C permits the on-site washout of both steel and synthetic fibres to determine the average content in a concrete mix on site.

Purchase your copy here